Centrifugal pipe head core



Jan. 11,1927. l

Filed Jan. 29. 1926 U s M l Q l 4 a s s INVENTOR Patented Jan. 11,1927.

UNITED STATES PATENT OFFICE.

WILLIAM D. MOORE, OF BIRMINGHAM, ALABAMA, ASSIGNOR TO SAND SPUN PATENTS CORPORATION, 0F WILMINGTON, DELAWARE, A CORPORATION 0F DELAWARE.

CAENTRIFUGAL PIPE HEAD CORE.

Application mea January 2s, 1926. serial No. s4,sso.

This invention is an improvement in centrifugal casting in sand molds, and more particularly in head cores for such molds.

In casting centrifugally in tiltable molds in the manner shown and described 1n my Patent Number 1,471,052, dated Oct'. 16, 1923, the charge is poured into the spigot end of the mold while the mold is inclined, the charge running by gravity toward the bell end.

Because of the inclination of the mold during charging, the end toward Whlch the metal Hows is usually closed by a head core, which provides an abutment to prevent overflow of the charge, and assists in shapmg the bell end of the casting.

Even with the most careful manipulation of the mold, to meet the charge, as specified in application No. 42,168, filed 'July 2.5, 1925, a part ofthe charge is liable to str1ke the face of the head core, and rapidly cooling, such portion adheres to the head core forming a thin .film over a part-or all of the. face.

In the preferred method, the mold 1s rotated at a relatively low speed during the charging, and at a relatively high speed during the casting, andthe change rom the low to the high speed is abrupt. Durmg the first stage, that is the charging, the speed of rotation is not suicient to hold the metal on the mold wall by centrifugal force, and the molten metal lies longitudlnally thereof, substantially in a mass, so'held by gravity. 0

. The charging operation takes place while thevmold is inclined, and is preferably finished co-incident with the complete restoration of the mold to the horizontal or level position.

When the mold is spun, that is when the relatively rapid rotation commences, or while it is proceeding, the film of artly cooled metal on the head core is t rown olf, and in the usual arrangement of head cores, it travels radially to the casting wall. The cooling of this film has advanced far enough. so that the film is Anot absorbed into the wall of the casting, but forms a roughness thereon, which later must be ground away.

One of the primary objects of the resent invention 1s the provision of a ead core of a formation such vthat the filrn of partially cooled metal will be retained on the head core.

The material from which the head cores are made is relatively expensive, because of the oil used therein, and another object of the invention is the provision of a core of a formation such that a minimum amount of sand and oil is required to make the same.

With these and other objects in view the invention consists. in the construction and novel combination of parts fully described hereinafter, illust-rated in the accompanying drawings, and pointed out in the claims appended hereto, it being understood that various changes in the form, proportion, size and minor details of construction within the scope of the claims, may 'be resorted to without departing from the spirit -of the invention.

In the drawings forming a part hereof;

Fig. 1 is a side view with parts in section. of apart of the apparatus for castin centrifugally in tilting molds, by the metho of the patent above mentioned.

Fig. 2 is a longitudinal section through that end of the mold provided with the head core and through the improved head core.

Fig. 3 is 'a sectional view showing a modified form of clore plate.

The embodiment of the invention shown in the drawings, is shown in connection lwith a sand .lined mold, including a flask oomposed of a body 1 and a lining or mold 2 of sand within the flask. The mold is supported on a tilting carriage 3 pivoted at 4 to swing into inclined or horizontal position, and the carriage is moved into tilted position by fluid pressure apparatus indicated generally at5. The weight of the carriage and associated parts is relied upon to return the mold to level or horizontal position, and the mold is rotated by means of a motor indicated at 6, which is mounted on the carriage, and has the motor shaft thereof re.- leasablv connected to the ask. Y

A bell shaped extension 7 is connected with one end of the flask, and the said extension has a marginal fiange 8, to-which is connected the flange 9 of aA sleeve l0, by means of key-pins 11. The head core 12 is of any usua or desired conformation, andA it is placed within the bell shaped extension 7 of the iask, .being held by the sleeve 10. The external contour of that portion of the flange which extends inwardly be ond the sleeve 10 corresponds to the desire internal contour of the bell end of the casting 13, and referring to Fig. 2 it will be noticed that the bore of the sleeve 10 at the flange is ta ering. i

El'he core is composed of sand and an oil, such as linseed oil, the parts being mixed in suitable proportions, until every particle ot the sand is coated with the oil. T he sand is then shaped to form the core wllich is afterwards dried by heat to volatilize the oil. Because the head core is at'the end toward which the molten metal is charged, it is desirable that it completely close the said end, and since it is the core for the bell end of the mold, it must be relatively long. Thus a relatively large amount of oil is required or each head core.

The core is reinforced and supported at the end which engages the sleeve 10, the said sleeve constituting the support for the core, by means of an internally flanged ring 14, Whose `peripheral surface tit-s the tapered portion ot the sleeve, and the core is held from outward movement by means of wedges 15, which are passed through radial openings in the sleeve, and against the inner ends of which the ilange of the ring 14 bears.

:in head vcores as heretofore constructed, the inner end thereof is of a conformation such that any molten metal treezing thereon during the charging, and slovv rotation of the mold, will be dung od during the casta ing stage, or rapid rotation oi1 the mold, onto the inner surface of the casting, there to torni a roughness which later must be ground away. lin the present invention the inner end et the mold is so shaped that such ad hering metal will he retained during the casting or rapid .rotationc To insure this end, the inner end ot the core is deepl recessed as shown at 16, the

recess extending axially and having its side wall et a conformation such that it will oppose radial movement ot metal within the cavity or recess under the induence of gravity. That is at least a portion of the wall at the open end or the cavity should be cylindrical or undercut to resist radial movement ot the metal. The retention of the metal is also facilitated by the depth ot the l cavity and the cost of the core is decreased by lessening the amount of sand and oil used. It will he evident that any congealed iron or metal which may temporarily adhere to the face of the head core is trapped, to prevent it from applying itself to or becoming incorporated with the casting wall.

While the method of preventing trapped metal' from reaching the core wall is exempliiied in a head core for castings with bell ends, it is obvious that it is equally applicay ble to castings with plain ends, or 1n any case where it is necessary to roduce a casting free from the troubles which are avoided by the use of the improved core. It is equally obvious that the use is not limited to cores of oil and sand. A,

AIn Fig. 3 a core is shown with an alteru nate form of core plate. 1n this construction the core 17 is supported by a plate 18, of tapering form externally like the platel. Instead however of being a ring only, the plate has a transverse partition 19. The partition is provided at the face adjacent the casting with an annular groove 20. The side walls are undercut as shown, which provides for a dove tailed effect or connection between the core proper and the core plate. When dry this connection provides a. perfect union until the casting operation is conipleted. The arrangement also enables the making of a very deep recess 21, the said recess extending almost to the core plate partition, and to the end of the casting.

I claim: A

1. A. core for that end of a centrifugally operated mold toward which the metal Hows in charging, having at its inner end or face an axial recessextending part way through the core.

2. A. core for that end ot a centritugally operated mold toward which the metal Howsl in charging, having at its inner end or tace an axial recess extending part way through the core, the side wall ot the recess shaped at the open end to oppose radial movement ot metal within the cavity by centrifugal action.

3., A head core for the end ot a centrifugally operated mold toward which the metal is charged having the inner end or tace thereof shaped to receive and retain excess metal ithrown thereon during charging against radial movement by centrifugal action.

el. .d lhead core tor closing the end ot a centritugally operated mold toward which the metal is charged, said core having an axial recess the wall at the open end thereof shaped to oppose radial movement of metal within the cavity by centrifugal action.

5. A head core ier closing the bell end ci a centritugally operated mold shaped to produce a casting with a bell end, the inner end of the core having means to receive and retain excess metal thrown thereon during charging against displacement by centritu? gal action during casting 6. A head core tor closing the hell end of a centrifugally operated mold shaped. to produce a casting with a bell end, the core shaped to serve as a core for the hell and to close the end, the inner end of the cere having means to receive and retain excess meta-l thrown thereon. during charging Mill ramasse against displacement by centrifugal action `during casting, said means including an axial recess in the core, the side Wall of the recess at the open end thereof substantially cylindrical.

7. The step in the method of centrifugally casting hollow bodies with bell ends in tilt ing molds, which consists in trapping any congealed metal which may adhere to the head core in charging and retaining Said metal during,I casting to prevent contact thereofo with the casting Wall.

8. A machine for centrifugally casting hollow bodies, including a tilting refractory lined mold, means to tilt the mold, and a head core of refractory material closing the lower end of the mold deeply recessed axially for the purpose set forth.

9. A machine for centrifugally casting hollow bodies, including a tilting refractory lined mold, means to tilt the mold, and a head core of refractory material closing the lower end of the mold deeply recessed axially for the purpose setforth, said recess formed to oppose movement of trapped metal toward the mold wall.

10. A machine for centrifugally casting hollow bodies, including a tilting refractory lined mold, means to tilt the mold, and a head core of refractory material closing the lower en'd of the mold deeply recessed for the purpose set forth, lthe recess formed to trap and retain congealed metal gaining access thereto.

11. A core for closing one end of a centrifugally operated mold having at the inner endv thereof an axial recess extending part Way Ethrough the core.

12. A core for the end of a centrifugally operated mold including a core plate and a refractory core body, the plate having an annular groove with undercut side walls, and the core body a similarly shaped rib fitting within the groove.

13. A core adapted for use in centrifugal casting', including a plate having at one fat-c an annular groove with undercut side Walls, and a body of refractory material having a. rib ttingrr within the groove, the end of the body remote from the plate having a relatively deep axial recess.

14. A core adapted for use in centrifugal casting, including a plate having at one face an annular groove with undercut side walls, and a body of refractory material having a rih fitting within the groove.

15. A core adapted for use in centrifugal casting, including a rigid plate and a body of refractory material, said plate and body having a dove tailed connection.

Signed at Birmingham, in the county of Jefferson and State of Alabama, this 15th day of January A. D. 1926.

WILLIAM D. MOORE.

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